The present invention relates to a dispensing packing for stick-shaped pasty products with a stationary external barrel or case for the decoration of the body.
Various types of dispensing packings for stick-shaped pasty products, goods or wares such as cosmetic products, adhesives or the like are known. For a long time, these packings are essentially made from plastics or synthetic material.
Nowadays it is frequent that such a dispensing packing comprises a hollow body inside of which a pasty stick is guided in a longitudinal direction between a retracted position and a position of use projecting from a first end of the body. Inside of the body is provided a device for the displacement of a stick, which consists of a sliding piston to which the stick is made fast and of a screw adapted to co-operate with the piston for moving it (and therefore for displacing the stick) in the longitudinal direction. A drive cap for rotating the screw is mounted at the other so-called "second end" of the body whereas the first end may be closed by a cap.
It moreover is usual that the piston comprises ports opening opposite to both ends of the body and that a tightness system, most often consisting of an interposed disposable capsule be provided between the first end of the body and the closure cap. It is thus possible to provide the stick directly within the packing by using the hollow body as a mold. More specifically the stick is obtained from the second end of the body by casting the selected product in the fluid state through the openings of the piston and then by solidifying this product inside of the body prior to the mounting of the drive cap owing to which the second end is closed generally.
This kind of packing of the prior art however exhibits many inconveniences. In particular it is difficult with the known packings to find for the body a material which meets in an economically acceptable manner both the mechanical requirements and the requirement of compatibility with the product of the pasty stick. Likewise with the packings of the prior art it is not easy to differentiate the aspect of the dispensing packing in accordance with the pasty product it contains. In other words except for providing different hollow bodies for a same type of packing, which is very expensive, all these packings are substantially identical irrespective of the pasty product they contain.
Still another major inconvenience of the packings of the prior art consists in that the device for moving the stick, i.e. the screw and the displacement piston should be mounted inside of the body through its first end. This increases in a useless manner the number of operating steps required for the assembling of the packing.
In addition the tightness systems of the known packings which consist generally of an inserted part like a capsule are not always perfectly effective for the casting of the stick and increase the cost price of the packing as well as the number of operating steps necessary to its assembling.
Furthermore the tightness system of the known packings should be withdrawn from the body before the first use of the stick, thereby being often felt as a wearisome operation by the consumer. Once withdrawn the tightness system is of course thrown away into trash independently of the remainder of the packing so that the recycling of the whole materials which constitute the latter may not be carried out simultaneously. Therefore once the tightness system has been withdrawn, the stick of pasty product has the tendency to become quickly altered mainly through evaporation of the volatile elements such as alcohols, water etc . . . contained within the pasty product of the stick.